JPH0957111A - Temperature-adjustable catalyst carrier or ozone decomposing element - Google Patents

Abstract

(57) [Summary] [Structure] Sheet, preferably a sheet-like catalyst carrier or ozone decomposing element and a sheet-like catalyst comprising a heating element such as a heating wire built in a low-density sheet or metal sheet containing inorganic fibers as a main component A block catalyst or an ozone decomposing element in which a sheet catalyst formed by supporting a catalyst on a carrier as well as the sheet catalyst or an ozone decomposing element are laminated so as to have a large number of small holes. [Effect] The sheet-shaped supported catalyst or the ozone decomposing element can be directly heated from the inside by the built-in heating element to maintain the temperature at the required reaction.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a catalyst carrier or an ozone decomposing element having a sheet-like or honeycomb shape or other small pores formed therein, and in particular, it is possible to freely raise the temperature of a catalyst or an ozone decomposing agent to enhance the reaction rate. The present invention relates to a catalyst carrier or an ozone decomposing element which can be regenerated and activated immediately by heating when the catalyst or the ozone decomposing agent is deactivated.

[0002]

2. Description of the Related Art The applicant of this patent is
Proposed an ozone decomposing element, which is formed by laminating a single-sided molded product made of paper, which is composed of organic and / or inorganic fibers, activated carbon fibers, and activated carbon fine particles. On the other hand, the applicant of the present patent application is Japanese Patent Application No. 2-417936 (JP-A-4-215936).
854), a method of obtaining a catalyst carrier by firing a honeycomb block obtained by laminating ceramic fiber paper with hot air having a low oxygen content and impregnating with a dispersion of catalyst particles and a dispersion of an inorganic binder was proposed. . Further, the applicant of the present patent application is Japanese Patent Application No. 4-45042 (Japanese Patent Application Laid-Open No. 5-64745).
In obtaining a honeycomb-shaped catalyst carrier in, a honeycomb-shaped laminated body is formed from paper having ceramic fiber, glass fiber or carbon fiber and mountain bark as main components, and a dispersion of catalyst particles and silica sol, alumina sol, etc. We proposed a method to improve the shape retention of honeycomb-shaped laminate by impregnating it with a dispersion of inorganic binder.

[0003]

The ozone decomposing element as described above decomposes ozone by the reaction of the activated carbon contained therein and ozone, and the catalyst carrier carries a catalyst thereon for use in the catalytic reaction of fluids. However, it is generally known that the reaction rate of the chemical reaction doubles every time the reaction temperature rises by 10 ° C., and depending on the outside air and other conditions, the temperature of the catalyst and thus the catalyst carrier or activated carbon rises. However, it may be required to accelerate a chemical reaction such as a contact reaction. Further, for a catalyst that can be heated and regenerated when the catalyst is deactivated, simple and rapid heat activation is required.

[0004]

Means for Solving the Problems The present invention meets the above-mentioned requirements, and a catalyst carrier having a large number of small through holes, such as a sheet or a honeycomb, whose temperature can be easily and reliably adjusted with a small amount of heat energy. An object of the present invention is to provide an ozone decomposing element, which aims to form a sheet-shaped catalyst carrier having a heating element or an ozone decomposing element and a sheet having the heating element formed therein with a large number of small holes. As described above, for example, it is achieved by providing a catalyst carrier or an ozone decomposing element laminated and molded in a honeycomb shape. On the other hand, in the case of a sheet-shaped or honeycomb-shaped supported catalyst, when the contact reaction is repeated for a long time, a substance having a high boiling point may be produced and adhered due to the polymerization reaction of the reaction substance, and the contact reaction may be hindered. In this case, the supported catalyst is heated to 300 to 450 ° C. for 1 to 3 hours to be activated by energization.

[0005]

EXAMPLE 1 As shown in FIGS. 1 and 2, the thickness is 0.1 to 0.1.
An adhesive, preferably an inorganic adhesive, is applied to one of two sheets of 0.2 mm glass fiber as a main component or one of two sheets of metal such as aluminum or a synthetic resin such as polyester, or 1 a, and both sheets 1, A large number of resistance wires 2 are sandwiched between 1a. When using a metal sheet, it is necessary to insulate the resistance wire. Sheet 1, 1
To dispose the resistance wire 2 between a and sandwich it, for example, as shown in FIG. 3 and FIG. 4, sheets 1 and 1a wound in a roll shape, a large number of resistance wires 2 and 2 wound on a bobbin, and a pressure roller 3 are provided. , 3,
An adhesive applying device 4 and a frame 7 in which guides 5 and resistance wire insertion rings 6 and 6 are arranged as shown in FIG. 4 are arranged, and an adhesive is applied to the sheet 1 and the sheet 1a by the adhesive applying device 4. The sheet 1b is guided between the pressure rollers 3 and 3, the resistance wires 2 and 2 are passed through the guide 5 and the resistance wire insertion rings 6 and 6, and the resistance wires 2 and 2 are placed immediately before the pressure rollers 3 and 3, respectively. It is sandwiched between 1b and the adhesive is heated and cured by the heater 8. The interval between the adjacent resistance lines 2 and 2 is about 2 to 4 mm. On the other hand, as shown in FIG. 3, soldered electrode 1
0 and 10 are pre-fixed and placed on the surface of the sheet 1 at desired intervals. The heating wire 2 and the electrode 10 embedded in the sheet 9 are heated and fused.

The obtained sheet 9 is cut as shown in FIG. 1 and lead wires 11, 11 are connected to the electrodes 10, 10 to obtain a sheet-shaped catalyst carrier. In this case, by dividing the electrodes at both ends as shown in FIG. 1, the electric resistance of the sheet 9 can be adjusted to determine the power consumption. Or lead wire 1
After connecting 1 and 11, this sheet-shaped body can be formed into a corrugated shape as shown in FIG. The power consumption of the resistance wire 2 is set so that the surface of the sheet becomes about 30 to 500 ° C. when energized. A catalyst, for example, 12 parts of Nickel Oxide manufactured by Nissan Gardler, was immersed in a suspension of silica sol, for example, a mixture of 30 parts of Nissan Chemical's Snowtex-08 and 30 parts of methanol, to make a solid content of 63% supported on the sheet. A sheet-shaped supported catalyst is obtained.

[0007]

Embodiment 2 As shown in FIGS. 6 and 7, the thickness is 0.1 to 0.1.
0.2 mm activated carbon fiber sheet or sheet produced by mixing activated carbon fine particles or sheet produced by mixing activated carbon fiber and activated carbon fine particles 1, 1a
An adhesive, preferably an inorganic adhesive, is applied to one or both of the sheets, and a large number of resistance wires 2a are sandwiched between the sheets 1 and 1a while being arranged in a meandering shape. To arrange the resistance wire 2a in a meandering manner between the sheets 1 and 1a, for example, the apparatus and method shown in FIGS. 3 and 4 are used. In FIG. 3 and FIG. 4, the frame 7 is constructed so that it can be horizontally swung, and the resistance wires 2a, 2
By passing a through the resistance wire insertion rings 6 and 6, immediately before the pressure rollers 3 and 3, the lateral swing frame 7 is swung in the width direction of the sheets 1 and 1a to move the resistance wires 2a and 2a. The sheets 1, 1a can be continuously sandwiched in a meandering shape.

The obtained sheet 9 is cut as shown in FIG. 6, the resistance wire 2a is connected in parallel to the electrodes 10 and 10 and connected to the lead wires 11 and 11 to obtain a sheet-like ozone decomposing element. The resistance wire 2a has a surface of the sheet of about 30 when energized.
The power consumption is selected so that the temperature becomes ~ 500 ° C. If necessary, activated carbon fine particles are fixed to the sheet 9 or the corrugated sheet in an amount of 5 to 30% by weight based on the weight of the sheet.

[0009]

Third Embodiment As shown in FIGS. 8 and 9, the thickness is 0.1 to 0.2.
mm flame-retardant paper 1 coated on one side with electrically insulating coating 12
Thus, the heating wire 2a is embedded in a meandering shape. In this case,
The apparatus shown in FIG. 10 is used. This device was previously shown in Figure 3.
Similar to that described with reference to FIG. 4, as shown in FIG. 10, a sheet 1, a roll-shaped separator film such as a polyester film 13, a large number of heating wires 2a and 2a wound on a bobbin, and a coating agent coating device 4 are provided. prepare. An electrically insulating coating agent is applied to one surface of the separator film 13 by the coating agent application device 4, and the heating wire 2a is moved in a meandering manner while being sandwiched between the sheet 1 and the separator film 13, and the separator film 13 is rolled. A layer of the winding coating agent 12 is dried on 14 to obtain a sheet 15 in which the resistance wire 2a is embedded.
On the other hand, as shown in FIG. 10, preferably, soldered electrodes 10a and 10b are fixed in advance on the surface of the sheet 1 at desired intervals as in the case of FIG. A chemical foaming agent is mixed as a coating agent, and the chemical foaming agent decomposes and foams during heating and curing by the heater 8 to form continuous pores in the coating agent layer and the catalyst impregnated in the sheet 1 comes into contact with the outside air on the surface of the coating agent. It is better to use what you get. The heating wire 2a embedded in the sheet 15 and the electrodes 10a, 10b are heated and fused from the outside of the sheet 15.

After impregnating and fixing the obtained sheet 15 with an inorganic reinforcing agent, a catalyst comprising 1.6 parts of Nissan Gardler copper oxide-manganese oxide, 4 parts of silica sol, 1.25 parts of water, and 1.25 parts of acetone. The sheet 15 is dipped in the suspension and the amount of the sheet 15 is about 10-15 wt. % Catalyst fine particles are impregnated and fixed. The sheet 15 is cut at the positions M and N in the figure with the electrodes 10a and 10b left at both ends, and lead wires 11a and 11b are connected to the electrodes 10a and 10b as shown in FIG. 8 to obtain a sheet catalyst. The power consumption of this sheet catalyst is selected so that the surface thereof is approximately 30 to 500 ° C. when energized.

[0011]

Fourth Embodiment As shown in FIGS. 11 and 12, the thickness is 0.1 to 0.1.
Prepare low-density sheets 1 and 1a containing 0.2 mm of heat-resistant synthetic fiber as a main component, and one surface of one sheet 1 is mixed with conductive paint, for example, synthetic resin and fine particles of carbon, silver or other electric conductor. A paste dispersed in an organic solvent is applied, the other sheet 1a is attached to the applied surface and dried, the electrodes 10 and 10 are connected to the conductive coating film 2e, and the lead wires 11 and 11 are attached to the electrodes 10 and 10. Wire connection is performed to obtain a sheet-shaped catalyst carrier. Catalyst sheets are obtained by impregnating and adhering catalyst fine particles onto the sheets 1 and 1a of the sheet catalyst carrier. The conductive coating film 2e is prepared by adjusting the composition of the coating material and the thickness of the coating film so that the surface of the sheet is approximately 30 to 150 ° C. when energized.

[0012]

Fifth Embodiment As shown in FIGS. 13 and 14, the thickness is 0.1 to 0.1.
Prepare a low-density sheet 1 or 1a containing 0.2 mm ceramic fiber as a main component, and a sheet heating element 2f formed by etching a metal foil such as a copper foil or an aluminum foil having a thickness of several hundred μ in an electric heating circuit. 1 and 1a are sandwiched and fixed, and the electrodes 10 and 10 are connected to both ends of the sheet heating element 2f to form the lead wire 1.
1, 1 and 11 are connected to obtain a sheet-shaped catalyst carrier, and the sheet-shaped catalyst is obtained by impregnating and supporting catalyst fine particles on the sheets 1 and 1a.

In the above-mentioned first to third embodiments, the resistance wire is nickel chrome alloy, nickel copper alloy or any other desired wire.
A resistance wire having a diameter of 1 to 0.3 mm is used by applying a bare wire or a film of polytetrafluoroethylene having a thickness of 5 to 10 μm or other suitable insulating coating. Further, in the above-mentioned Examples 1 to 5, a porous sheet such as pulp capable of fixing or impregnating and fixing catalyst particles or the like can be used as the base sheet, but in order to prevent ignition and other accidents due to heat, ceramic fiber, glass Inorganic non-combustible fibers such as fibers, activated carbon fibers, sheets containing heat-resistant synthetic fibers as a main component, flame-retardant paper, activated carbon mixed paper, metal sheets and the like are desirable.

As the catalyst to be supported, any catalyst which can be used for the reaction of gas at an appropriate temperature can be used, but examples thereof include carbon monoxide, hydrocarbons and nitrogen oxides in the exhaust gas of internal combustion engines such as automobiles. Catalysts for purification treatment, for deodorizing waste gas, such as iron, cobalt, nickel, manganese,
Copper, silver, chromium, molybdenum, tungsten, titanium,
Vanadium, zircon, zinc, germanium, tin,
Lead, phosphorus, antimony, bismuth, rare earth elements, alkali metals, alkaline earth metal nitrates, chlorides, sulfates,
Carbonate, organic acid salt, ammine complex salt, hydroxide, oxide, etc., platinum, palladium, rhodium, ruthenium, iridium nitrate, chloride, ammine complex salt, etc., activated carbon for ozone decomposition, other catalysts such as alumina, nickel oxide , Manganese dioxide or a mixture of manganese dioxide and cupric oxide or ferric oxide, zeolite, and the like.

[0015]

[Sixth Embodiment] In the first embodiment, the sheet-shaped catalyst carrier shown in FIGS. 1 and 2 except the lead wire 9 and the corrugated sheet 9a are used.
Are laminated and bonded as shown in FIG. 15 to obtain a single wave molded body. A sheet in which the heating wire 2a is arranged in a meandering manner in Example 2,
The same applies to the other Examples 3 to 5. As shown in FIG. 16, this single-sided molded body is laminated or not laminated to form a rectangular honeycomb block 16. After that, 12 parts of nickel guard oxide made by Nissan Gardler was added to silica sol, for example, snow tex-08 part of Nissan Kagaku, and 3 parts of methanol.
After dipping in a suspension dispersed in a mixed solution with 0 parts, 150 ° C
Dry with hot air for 30 minutes. This operation was repeated 3 times. As a result, the honeycomb block was impregnated with 63 wt% of nickel oxide. Both ends of each electrode 10, 10 of each sheet in this honeycomb block are connected to electrodes 10a, 10
a to the lead wires 11 and 11 connected to the electrodes 10a and 10a.
And a power source is connected to obtain a catalyst-supporting honeycomb body. The single wave molded body may be wound and laminated as shown in FIG. 17 to form a cylindrical honeycomb block, and lead wires 11 and 11 may be connected to the ends of the electrodes 10 and 10 at both ends to be connected to a power supply.

[0016]

[Embodiment 7] In Example 2, a large number of sheets 9 shown in FIGS. 6 and 7 except for the lead wires 11 are stacked as shown in FIG.
Adhesive 18,18 ..., 19,1
.. are linearly applied, the respective sheets are pressure-bonded to each other, and then the respective sheets are pulled open as shown by an arrow in the drawing to obtain a honeycomb laminated body as shown in FIG. Both ends of each electrode of each ozone decomposition sheet 9, 9 are connected to an electrode, and a lead wire is connected to this electrode and connected to a power source to obtain an ozone decomposition honeycomb body.

[0017]

[Embodiment 8] Except for the lead wires 11 and 11 of the catalyst-supporting sheet 9 of Embodiment 1, as shown in FIGS. 21, one end of each electrode 10, 10 of each catalyst supporting sheet is connected to the electrodes 10a, 10a.
And the lead wires 11, 11 are connected to the electrodes 10a, 10a and connected to a power source to obtain a supported catalyst. As shown in FIG. 22, the catalyst-carrying sheet 9 is formed into a cylindrical shape with a spacer 20 sandwiched therebetween, and a gap is maintained between the sheets, and the lead wires 11 and 11 are provided at one ends of the electrodes 10 and 10 at both ends.
You can also connect to and connect to the power supply. The same applies to the sheet-like ozone decomposing element.

[0018]

The sheet-shaped catalysts or ozone decomposing elements obtained in Examples 1 to 5 are energized to maintain the reaction temperature at an optimum level, and the gas or the air containing the gas or the like which should proceed the reaction Contact with an inert gas to accelerate the reaction. The supported catalysts or ozone decomposing elements having small pores obtained in Examples 6 to 8 are energized to maintain the reaction temperature at an optimum level, and the gas or the air containing the gas or the like to proceed the reaction An inert gas is passed through the small holes to promote the reaction. When the reaction product adheres to a sheet-shaped catalyst or a block-shaped supported catalyst or the performance as a catalyst deteriorates due to other causes, the temperature of the sheet is raised to about 200 to 400 ° C. by energization, and the time is from 1 to 4 hours. By doing so, the impurities can be decomposed and removed to restore the performance as a catalyst.

With the honeycomb-shaped catalyst obtained in Example 6, the thickness of the glass fiber sheet was 0.1 to 0.12 mm, the wavelength of corrugated paper was 2.65 mm, the wave height was 1.6 mm, and the length of the small through holes was 30 m.
A block of m was loaded with 63% by weight of Nissan Gardler's nickel oxide and the heating wire of the sample was energized to adjust the temperature to 60 ° C., and 1 m of air containing 1 ppm of ozone was added to this.
sec. When ozone was continuously decomposed at the speed of, the decomposition rate was 99% in the initial stage and 98% after 450 hours as shown in FIG. 23 (curve). On the other hand, as a comparative example, when the heating wire is not built in, 99% can be decomposed and removed in the initial stage of the (curve) as in the case where the heating wire is built in, but after 450 hours, the removal rate becomes 95% and the heating wire is built in. The removal efficiency is reduced in comparison. This is because, in the present invention, the heating wire incorporated in the block sheet is heated to a temperature of about 60 ° C., so that the nickel oxide catalyst fixed or impregnated and fixed to the sheet always operates at the optimum temperature.

[0020]

In the prior art, for example, when air containing a small amount of nitrogen oxides or ozone is passed through a catalyst or activated carbon to decompose and remove the small amount of nitrogen oxides or ozone, a large amount of air is used up to the optimum reaction humidity. It was necessary to heat and pass this through a catalyst or an ozone decomposing element, but since the catalyst carrier or the ozone decomposing element of the present invention was constructed as described above, it could be rapidly and uniformly applied in sheet form over the entire area by electrification. The block-shaped supported catalyst or the ozone decomposing element can be heated to a predetermined temperature, the heat energy can be used efficiently, and a large amount of heat energy can be saved. Further, when the heating wires are arranged in a parallel meandering shape on the sheet, the density of the heating wires can be further increased to reduce the temperature unevenness. Moreover, the thermal expansion of the sheet of the base body and the thermal expansion of the heating wires can be reduced. By buffering the difference, there is an effect that distortion of the sheet due to heat can be prevented.

On the other hand, in the process of producing a sheet catalyst, for example, in the case of producing a sheet catalyst of manganese dioxide, conventionally, an appropriate sheet is first immersed in a pure manganese nitrate aqueous solution in order to enhance the performance as a catalyst. After drying, the manganese dioxide was produced on the surface of the sheet by firing at about 200 ° C. for an appropriate time. However, if the sheet-shaped catalyst carrier of the present invention is used, the heating element is built in the sheet-shaped catalyst carrier, so that the electric current is controlled. Therefore, the calcination temperature can be adjusted to easily, quickly and reliably obtain the sheet catalyst.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a sheet-shaped catalyst carrier.

FIG. 2 is a left side view of FIG.

3 is a principle view showing an example of an apparatus used for producing the sheet-shaped catalyst carrier of FIG.

FIG. 4 is a partially enlarged plan view of FIG.

FIG. 5 is a perspective view of a corrugated sheet-shaped catalyst.

6 is a plan view showing an example of a sheet-like ozone decomposing element that is partially peeled off along the line BB in FIG. 7. FIG.

FIG. 7 is a right side view of FIG.

FIG. 8 is a plan view showing another example of the sheet-shaped catalyst partially peeled along the line EE in FIG.

9 is a sectional view taken along line DD of FIG.

10 is a principle view showing an example of an apparatus used for manufacturing the sheet-shaped catalysts of FIGS. 8 and 9. FIG.

FIG. 11 is a plan view showing still another example of the sheet catalyst.

FIG. 12 is a sectional view taken along line FF of FIG. 11;

FIG. 13 is a plan view showing still another example of the sheet catalyst partially peeled along the line HH of FIG. 14.

FIG. 14 is a sectional view taken along line GG of FIG.

FIG. 15 is a perspective view showing a one-sided molded body of a sheet catalyst or an ozone decomposing element.

FIG. 16 is a perspective view showing an example of a honeycomb-layered supported catalyst or an ozone decomposing element.

FIG. 17 is a perspective view showing another example of a supported catalyst in the form of a honeycomb laminate or an ozone decomposing element.

FIG. 18 is a cross-sectional view showing a method of manufacturing still another example of the honeycomb laminated body-like ozone decomposing element.

FIG. 19 is a cross-sectional view showing still another example of a honeycomb laminated body-like ozone decomposing element.

FIG. 20 is a perspective view showing another example of a block-shaped supported catalyst.

FIG. 21 is an enlarged view of portion e in FIG.

FIG. 22 is a perspective view showing still another example of a supported catalyst.

FIG. 23 is a graph showing test results of an example of a supported catalyst.

[Explanation of symbols]

 1 Sheet 2 Resistance Wire 3 Pressure Roller 10 Electrode 11 Lead Wire 13 Separator Film 16 Honeycomb Block

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B01J 23/14 ZAB B01J 23/16 ZABA 23/16 ZAB 23/38 ZABA 23/38 ZAB 23/70 ZABA 23/70 ZAB 35/04 301P 35/04 301 B01D 53/36 ZABF ZABC

Claims (11)

[Claims] 1. A catalyst or an ozone decomposing agent is fixed or impregnated and fixed to the inside and the surface of a sheet containing a heating element, and electrodes are connected to both ends of the heating element so that the temperature can be controlled by electric heating. A catalyst carrier or ozone decomposing element capable of controlling temperature, which is characterized. 2. A catalyst which is fixed or impregnated and fixed in a sheet containing a heating element or on the surface thereof is iron, aluminum, cobalt, nickel, manganese, copper, silver, chromium, molybdenum, tungsten, titanium, vanadium, zircon, zinc, Germanium, tin, lead, phosphorus, antimony, bismuth, rare earth elements, alkali metals, alkaline earth metal nitrates, chlorides, sulfates, carbonates, organic acid salts, ammine complex salts, hydroxides, oxides, platinum, The catalyst carrier or ozone decomposing element capable of controlling temperature according to claim 1, which is a nitrate, chloride, ammine complex salt of palladium, rhodium, ruthenium or iridium or a mixture thereof, or a zeolite. 3. An activated carbon fiber sheet or a sheet produced by mixing activated carbon fine particles or a sheet produced by mixing activated carbon fibers and activated carbon fine particles has a heating element built in, and electrodes are connected to both ends of the heating element to conduct electricity. An ozone decomposing element capable of controlling the temperature, characterized in that the temperature can be regulated by heating. 4. The catalyst carrier or ozone decomposing element capable of adjusting the temperature according to claim 1, wherein the heating wires contained in the sheet are embedded in a parallel or parallel meandering shape. 5. The catalyst carrier or ozone decomposing element capable of controlling the temperature according to claim 1, wherein a conductive coating film is built in the sheet as a sheet heating element. 6. The catalyst carrier or ozone decomposing element capable of controlling temperature according to claim 1, wherein a metal film is built in the sheet as a planar heating element by an etching method. 7. The temperature-controllable catalyst carrier or ozone decomposing element according to claim 1, wherein the sheet is a sheet or metal sheet containing inorganic fibers, carbon fibers, pulp or heat-resistant synthetic fibers as a main component. 8. A temperature characterized in that sheets having a heating element built-in or embedded and having a catalyst or an ozone decomposing agent fixed or impregnated and fixed are laminated to form a honeycomb shape so that each heating element can be energized. A catalyst carrier or an ozone decomposing element capable of controlling the temperature. 9. A sheet having a heating element built-in or embedded and having a catalyst or an ozone decomposing agent fixed or impregnated and fixed is stacked with a spacer interposed therebetween to form a small through hole so that each heating element can be energized. A catalyst carrier or ozone decomposing element whose temperature can be adjusted. 10. An activated carbon fiber sheet or a sheet made by mixing activated carbon fine particles or a sheet made by mixing activated carbon fibers and activated carbon fine particles is laminated with a sheet containing a heating element to form a honeycomb shape. An ozone decomposing element capable of controlling temperature, characterized in that each heating element can be energized. 11. An activated carbon fiber sheet or a sheet made by mixing activated carbon fine particles or a sheet made by mixing activated carbon fibers and activated carbon fine particles, and a sheet having a built-in heating element is stacked with a spacer in between to form a small transparent sheet. An ozone decomposing element capable of controlling temperature, characterized in that holes are formed so that each heating element can be energized.